Geometry
posted by Angel .
Find, to the nearest tenth of a centimeter, the length of a diagonal of a square if the measure of one side is 8.0 centimeters.

Pythagorean Theorem
a^2 + b^2 = c^2
8^2 + 8^2 = c^2
64 + 64 = c^2
11.3 = c 
The diagonal of a square measures 12 feet.
a. What is the exact measure of a side of the square?
b. What is the area of the square 
Use the Pythagorean Theorem.
What do you get for the measurement of a side of the square? 
I manage to get X^2+X^2=144

Right so far.
2x^2 = 144
x^2 = 72
x = 8.4852813
Each side = 8.4852813 feet
A = s^2
A = 72 square feet